Writer: Tim W. McAlavy, (806) 746-4051,firstname.lastname@example.org
ORLANDO, Fla. — Producers and agricultural researchers say precision agriculture technologies are promising tools despite their often times high initial costs. That was the view expressed by a panel of farmers and university researchers at the recent Beltwide Cotton Conference here.
Dr. Craig K. Kvien, University of Georgia crop scientist and chair of the National Environmentally Sound Production Ag Laboratory in Tifton, Ga., said that precision agriculture is in its infancy, but that some producers and researchers already using it are seeing positive results.
“One of the our more promising experiments in precision agriculture is developing variable-rate irrigation guidelines for center pivots,” said Dr. Dan Krieg, professor of crop physiology at Texas Tech University in Lubbock. “We are using different sensors to vary the amount of irrigation water we apply to cotton. We re also comparing the timing of these irrigations.
“Our pivot is set up to deliver a constant volume of water. By changing the speed of the pivot, we can change the amount of water applied to a certain portion of the crop. We hope to correlate application rates with various stages of crop growth and come up with variable rate guidelines that will help producers improve their water- use efficiency, reduce irrigation costs and maximize crop yield potential.”
Another Texas Tech experiment with variable-rate irrigation compares the performance of several squeeze pumps and injections pumps used in chemigation (applying crop chemicals through an irrigation system).
Lubbock cotton grower Eugene A. Coleman outlined the cost of managing cotton in small grids, or zones, rather than managing entire fields as one production unit.
“Breaking a field up into several grids or zones and taking several soil samples per grid can be an expensive proposition, even if you pull all the soil samples yourself,” Coleman said.
“We pull our own samples, and our cost-per-acre for tradition soil sample analysis runs about $2 to $3 per acre. That cost goes up to about $5 to $7 per acre if your analysis includes micronutrients.”
“On the Texas South Plains, commercial fertilizer companies charge about $10 to $14 per acre for grid soil sampling with traditional analysis. That cost seems high, but it’s not unreasonable considering the amount of labor involved.”
Coleman said grid soil sampling is helping him learn to apply fertilizer in prescription amounts on each field grid, rather than using more costly blanket applications across an entire field. Still, he hopes producers will soon have the tools necessary to generate yield maps for each grid and for entire cotton fields. Without such a tool and maps, his prescription fertilizer applications will only return limited financial benefits, he said.
Other growers on the panel echoed Coleman’s call for better cotton yield mapping technology.
“We also need more durable and more reliable precision ag hardware (such as monitors and sensors),” said Georgia grower Ike Newberry. “I like the idea of managing my fields by zone, or grid, but it s going to be several more years before I have enough data to formulate improved ‘common sense’ management strategies from precision field data.”
Tennessee grower J. Michael Escue encouraged precision ag equipment companies to develop software programs that are more user-friendly.
“I have to rely on several hired hands to do my field work, and that is where crucial data collection takes place. I would like to see software available that is easier for my employees to learn and use,” he said. “If they aren t comfortable with the equipment and software, mistakes will be made. I can’t afford to base my management decisions on data that might be flawed.”
Louisiana grower Jon W. Hardwick cited a need for better data storage systems and computer software that is compatible with an array of available data storage systems.
The panel of growers advised other producers to slowly adopt these developing technologies. They said a yield monitor is perhaps the most important and affordable tool to start with, and added that grid field management is at its best when 2.5- to 5-acre grids are used.